Expression control



Jan. 7, 1930. I R BUKW 1,742,341

A Y EXPRESSION CONTROL Filed Nov. 19, 1927 V.5 Sheets-Shea?l l fr annundllonaaaauaa ununnnonnnnnnunug:

Jan. 7, 1930. R. BuKow EXPRESSION CONTROL Filed Nov. 19, 192'? 5 Sheets-Sheet 2 Jan. 7, 1930. R. BuKow EXPRESSION CONTROL Filed Nov. 19.. 1927 45 Sheets-Sheet 5 Jan. 7, 1930.A R. BUKow 1,742,341

EXPRES SI ON CONTROL Filed Nov. 19, 1927 5 Sheets-Sheet 4i l5 .WV-I n l f lp' Q 'y TTORNEY Viiection with the accom UNI-free: sra-resi PATENT goFI-iicl.;

Reina-OLD Burrow, on Lone rsLANnerrY, new

YORK, ASSIGNOR TO HARD'MAN, PEGI( & 00.*, F NEW'YQRK, N, Y., A CORPORATON OF NEW YORK EXPRESSION; CONTROL' Application filed yNovember 19, 1927. Serial No. 234,359.

'lhisinvention relates to mechanism used in connection with a. player piano action whereby. different shades ofV musical expression arev directly. reproduced in` accordance with certain perforations provided on the music sheet. `In theeinbodiinent of the invention sliownthedegree-or theshade of `expression is determined: by the magnitude of eX- haust transmitted from, the mainv exhausting means to the-strikerpneuinatics of the play,- er actioiiandthe inagnitudeof force transniittedds under control of: certain pneumati-` cally actuated valves and means are provided 'for augmenting the opening .movements of certain valves inaccoidalle with the perforations iii a music sheet.`

The invention will be fully apparent` from the 'following speciiication when read in conwill. bedetined with particularity in` theappended claims.

In the drawings, Fig. l isa diagram showing aV conventional. trackerr bar.player vaction and exhaustingineans combinedwith my imf proved, expression, mechanism; I

Fig, 2, is a vertical. longitudinalsecticn throughV the expression`r mechanism, the;A section, being taken on the line 2,--2A of, F igA I3, certain. valves being shown 1n. thev position they assume Awhen the tliiicldegiee of expression"` above initial tensionis eective; Y

Fig-3 is a. .horizontal `section on lineA 3,.-3

.of Fig. 2,;

Fig. 4 isa similar. horizontal'section taken approximately on lilie44 of Fig.V 2; parts beingbroken-away to reveal details below the normal plane of section; y

Fig. is a vertical cross-section Ion line 5 5 of. F 2Htliroughthe so-called initial tension or pianissimo; (PP)k pneumatic; 4 t

Fig. isa section on staggered line 6 -6 of Fig.,2 through the piano (P) pneumatic;

Fig. 7 is a section on line 7--7 of Fig-.2 througlithe forte pneum atie;y

Fig 8 is diagrammatic View illustrating an alternative arrangement of certain parts.

Referringindetailto,the-drawings10 represents theusual rtracker bar haviiigal plurality oit openings.y 12 therein, usually eightyeight. innuinber corresponding to .the eightypanyingv drawings and l eight notes oi' keys in ar piano. Iiiaddition to the openings12atfone end-the tracker bar is pi'ovidedfwith openings a, Y), c and ,these being connected` by duc-ts 1, 2, 3 and 4, with the separate expression control devices to be y `.u iaster hand-played record."`4

Fach of the note openings 12 inthe tracker bar is connected by a suitable duct 14 with a chamber-16 in the `player actionelement 18; There area multiplicity of these elements 18 and they collectively form what in the artis. called aplayer. action. When air is admitted tothe chamber lof the-action a` diaphragm 20.is liftedv andvthis raises a valve 2 2- which permits exhaust from Chamber 24 to commuiificatethrough passage 26 with asmallaction pneumatic28. The collapsing 'ofthis pneumatic swings a projection 3 0 thereonwhich in turn transmits its 'movement to an extension 32 formed onv the sticker' bar 34,*the `upper end ot whichsti'ikes the. whippen 36 whichis pivotedat 3S. This whippen as is well known transmits `the motion of the pneumatic to the hammery of the piano action whichstrikes the string. All'of the pneuinatics 28 ofthe player action communicate with a chamber,y or wind .chest 24 ksuch as shown in Fig. 1 and each wind chest 24 communicates witha main duct 4010i the player action which is connected by means of a pipe or other conduit 42 with a chamber 44 formedA in the expression unit.

The expression unit indicated as a Whole at E in Fig. 1 is connectedbyineans of' a suitable tube or conduit 46A with anlexhausting device which in the case illustrated' comprises bellows 48 actuated by a suitable foot-treadle 50, said bellows being.- connected with .an equalizer bellows 52.

The magnitude of exhaust transmitted from the exhausting means 4Sv to the striker pneumatics of the player action is. controlled ioo by the port area of certain valves to be hereinafter described which form component parts of the expression mechanism embodying my invention.

In the embodiment illustrated, I provide for four different shades of musical expression above pianissimo (PP) or normal tension.

Piano (P) or irst step above initial tension tone is controlled jointly by bellows A, A and A2, (Fig. 4).

Mezzo-forte tone or second step above initial tension is controlled by bellows B acting in conjunction with bellows A.

Forte tone or third step above initial tension is controlled by pneumatic C acting in conjunction with pneumatic A. The pneumatics B and C are connected by a bar 54 so that they move together1 and said pneumatics are inverted as compared with the pneumatics A and A' and the arrangement is such that a collapsing movement of either pneumatic B or-C will tend to expand pneumatic A. This is brought about by means of a rocking arm 56 pivoted at 58 to bracket 60, the arm being connected by a link 62, to

the upper end of pneumatic C, said link being connected at its lower end by means of a link 64 with the pneumatic A. As thus arranged, it is clear that when either pneumatic B or C is collapsed the pneumatic A will be expanded.

The pneumatics A, A', B and C are se- Vcuredto the back wall of the expression unit wind chest element indicated as a whole at W. This wind chest includes chambers 66, 68, 70, 72 and 74, the chamber 66 being connected with the aforementioned suction producing means by the conduit 46. Communication between chambers 66 and 68 is controlled by a pouch actuated valve 7 6 located opposite the port 7 8 connectingsaid chambers. The chambers 68 and 70 are connected by a port 80. Communication between chamber 70 and 7 2 is controlled by a pouch actuated valve 82. Both chambers 72 and 74 are adapted to communicate with the chamber 44 which is connected by means of the conduit 42 to the player action. The ports 84 connect the chamber 72 with the chamber 44. Similarly, ports 86 and 88 c onnect the chamber 74 with the chamber 44. The passage of air through ports 86 and 88 is controlled by pouch actuated valves 90-92,

.and these valves are only opened at such times that the tracker openings I) and 0 are uncovered by the perforations b1 and c1 of the music sheet, as hereinafter described.

Bellows A at all times is in communication with the chamber 72 through port 94. This bellows is also normally in communication with chamber 74 through port 96 but the effective area of port 96 is controlled by a flap valve 98 which comprises a substantially rectangular block having a piece of soft leather or sheep-skin glued to one face thereof, the upper end 100 of said leather forming a pivotal support for the valve. spring 102 serves to press the valve 98 toward its` seat but the valve is normally held open a slight distance by means of a stop 99 (Fig. 8) secured to the movable board 104 of the bellows, said stop engaging the extension 106 of the flap valve. The pneumatic A is normally distended by means of a spring 10S- hence at all times the valve 98 is held partially opened by means of pneumatic A. The amount of valve opening thus secured is suiiicient to pass enough exhaust wind to produce the lowest or softest tones herein spoken of as initial tension. To secure piano (P) expression, I provide means of augmenting the opening movement ofthe flap valve 98, this being effected through linger 99 by the actuation of the pneumatic A2 located within the pneumatic A.

foration al of the music sheet uncovers tracker opening a. This permits atmospheric pressure flowing through duct 1 to lift pouch 110. This causes valve 112 to be lifted so as to shut off wind from the interior of pneumatic A to the interior of pneumatic A2 and at the same time valve 114 is lifted so as to admit atmospheric air through port 116 to the interior of pneumatic A2, which course results in augmenting the opening movement of the flap valve 98. The chamber 111 above the pouch 110 is normally under the iniuence of exhaust wind which is communicated through port 113 leading to the interior of the pneumatic A1.

When piano (P) expression is transmitted to the player action, it is understood that valves 82, 90 and 92 are closed and that exhaust is transmitted from the exhausting means to the player action through a port area which is controlled by the flap valve 98. The exhaust so transmitted passes from chamber 68 through a port 118 controlled byv a pivoted flap valve 120 into the bellows A and through port 122 to chamber 7 4 thence through port 96, past lap valve 98 and out Ythrough port 94 to chamber 72 and ports 84 to chamber 44 thence by Way of conduit 42 to the striker pneumatics of the player action.

To secure forte mezzo expression, a perforation b in the music sheet uncovers the port Z) inthe tracker bar. This admits atmospheric air through duct 2 which results in lifting the pouch 124. This results in lifting valve 126 and thus opens communication between chamber 128 and the interior of bellows B through port 130. The chamber 128 is connected by means of port 132 with the interior of bellows A which it will be Vremembered is in communication with the vacuum Vchamber 68. Thus the effect of opening valve 126, causes the pneumatic B The pneumatic VA2 is brought into play whenever the per- Cil i mospheric `ing the ver 56 and links i greater perforation-d i? bar. This permits atmospheric air flowing ports 84 to the conduit 42 u simotones are produced.

results in further expanding, the pneumatic A. lThis pneumatic carries a finger `134 which upon the expanding movement of the pneumatic increases the opening. movement of the flap valve 120 thereby lincreas- 'Ilhe lifting of valve 126 also opens communication from chamber 128 to chamber 91 below the pouch valve 90, the chamber 91 being connected by` means of a duct186 with a` port 138'located adjacent the valve 126 as shown in Figs. 2 and 4. So long as valve 126 remains in its raised position, suctionV willV hold the valve open andk permit a high degree of suction to be transmitted through the port 862 to the player action. Thus the exhaust wind may be said to be shunted around the` pneumatic A. Similarly, when `the perforation c in the music sheet uncovers tracker opening c, at-

pressure transmitted through the duct 3 will llift pouch 140 which in turn will lift valve 142 to theposition shown in Fig.` 2. This will establish communication from chamber 128 to chamber 93A located below valve ,92 through duct 144. Thus the pouch will be collapsed and the valve 92 opened so as to uncover port `88. At the same time, suction from chamber 128 will be transmitted through port 146 to the interior of bellows C as indicated in Fig. 7. This will collapse bellows C and through rocking'le- 62 and 64 pneumatic A will be further expanded with the result that a opening of flap valve will be effected. Itis noted that the size of bellows C is greater'than that of bellows B-hence itwill be appreciated that pneumatic C will exert agreater openingfmovement onthe valve 120 than that exerted by pneumatic B.

To secure the loudest tones. the fortissimo uncovers port l of the tracker through duct 4 to lift `a pouchV 148 andlift valve150. .This act cuts off communication from chamberV 152 (which is connected with exhaust chamber 70 byy :conduit 153) to chamber 154 below t-he pouch 156. The

chamber 1541is connected by a conduit 158 .with a port 160 located above thevalve 150. then the valve lifts it also lifts a valve 162 locatedin a chamber l164 which is open 'to atmosphere. Thus atmospheric air flowthrough port and conduit 158 acts on the pouch 156 thus lifting the valve 82. This provides a direct passageway for a high degree of suction through chamberI 72 and leading to the player action. Because of this unrestricted flow, a high magnitude` of suction is transmitted to the action'and the loudest fortis- For convenience in'manufacture and asn :with a port area controlled by said valve.

too high semblyvof parts, the windA chest, WV, is provided with;l connections 168, and 172 connected; with various pneumaticsusually einployed inplayer. pianos which are not shown as they form no part of the present invention.

The expression mechanism is equipped also spring pressed.` exhaust valve 174 located in chamber 1376` which is open to atmosphere. This valvel is adapted to be actuated by the pouch 178 which is lifted when atmospheric air is admitted through a tube`180 upon the'opening of a silencer push button 182. The opening offlap valve 174 is accompanied by a closing movement of valve 76. Thus it is seen that when the pouch 178 is lifted, suction from the main bellows is entirely cutoff and the player action and expression mechanism is vented to atmosphere and is, therefore, rendered non-operative. This silencer push button is usually U actuated when it is desired to suppress the playing Aof certain parts of` aselection represented by the perforated music sheet. As soon as they silencer button is released`,the playing will be resumed.

Inthe arrangement above described, the ducts 2 and 3 lead directly from the tracker bar ports and c to the chamber 128. Such an arrangement operates satisfactorily in connection with music sheets inwhich no two expression `perforations are in alignment. The arrangement is. also satisfactory even though the expression perforations are in alignment provided the instrument is manu ally pumped. YVith a motor pump instrument it is desirable to provide means for preventing simultaneous actuation ofthe valves 126 and 142 so ask to prevent transmissionof a degree of suction to the player action. Ordinarily, ladapted for use with the instrument illustrated do not have expression' p'erforations arranged in horizontal alignment, therefore, if proper rolls are used, the tracker ports Z) 4and f c will never kbe simultaneously uncovered. However, users of: musical instru'- mentsV frequently buy their music rolls indiscriminately and certain manufacturers provide rolls in which the sheets are provided with expression perforations in horizontal alignment.

To meet this situation, I may provide the alternative arrangement shown in Fig. 8 in which a valve box 184 is interposed betweenthe tracker bar port o and chamber below pouch 124 (Fig. 2). The

valve box 184 includes a chamber 186 containing a valve 188 which when lifted closes off communication .between ports 190. and 192. Thus, it is clear that when the valve 188 is elevated even though port b in the tracker bar is uncovered, such uncovering of the tracker bar port by an abnormal music sheet will not be effective to lifty pouch 124 and valve 126. The valve 128 is arranged. to be lifted by a pouchv 194 whenever the tracker port c is the rolls or music sheets f uncovered by a perforation in the music sheet. The pouch 194L is located above the chamber 196 which communicates with a branch 3 connected to a Y fitting 3" interposed in the expression duct- 3. Above the pouch 194 there is a vacuum chamber 198 which connects by means of a pipe 200 to a vacuum chamber 128, Fig. 2. A suitable bleed-port not shown will permit communicat-ion between chambers 196 and 198.

Nhile I have described quite speciiically the details of the embodiment of the invention illustrated, it is not to be construed that I am limited thereto since various modifications and substitution of mechanical equivalents may be made by those skilled in the art without departing from the invention as defined in the appended claims.

That I ch im is Y 1. In combination with the striker pneumatics and exhausting means of a pneumatic musical instrument, an expression control mechanism comprising` a plurality ci pneumatics which are normally under exhaust, valves coacting therewith and one of which is always open during normal operation, and means for augmenting the opening movements of said valves so as to vary the air rarefaction or magnitude of exhaust transmitted to said striker pneumatics.

2. In combination with the striker pneumatics and exhausting means of a pneumatic vmusical instrument, an expression control mechanism comprising` a plurality of pneumatics which are normally under exhaust, normally open valves coacting directly with each of said pneumatics, and supplemental means controlled by the music sheet for augmenting the opening` movements of said valves so as to vary the air rare-faction or magnitude of exhaust transmitted to said striker pneumatics.

3. In .combination with the striker pneumatics and exhausting means of a pneumatic musical instrument, an expression control mechanism comprising a plurality of pneumatics which are normally in communication with said suction producing means, a chambered wind chest between the latter means and said pneumatics, valves within respective pneumatics controlling the magnitude of exhaust from the wind chest through said pneumatics, means moved by said pneumatics tor actuating said valves, and means for augmenting the opening movements of said valves. l

L1. In combination with'the striker pneumatics and exhausting means of a pneumatic musical instrument, an expression control mechanism comprising a plurality of pneumatics, a wind chest having chambers formed therein, respective valves tor said pneumatics controlling communication between each pneumatic and an associated chamber `1n said wind chest, means whereby said pneumatics actuate said valves and supplemental means arranged to operate in conjunction with said pneumatics for modi-tying the movement of said valves.

5. In combination with the striker pneumatics and exhausting means of a pneumatic musical instrument, an expression control mechanism including a wind chest having one chamber communicating with said exhausting means and another chamber communicating with said striker pneumatics, a pneumatic having a valve operatively connected therewith adapted to control the port area through which exhaust is transmitted 'from one oi' said chambers to the other, a supplemental pneumatic and connections whereby a collapsing movement of the supplemental pneumatic influences the opening movement of said valve.

6. In combination with the striker pneumatics and exhausting means of a pneumatic musical instrument, an expression control mechanism including a wind chest having one chamber communicating with said exhausting means and another chamber communicating with said striker. pneumatics, a pneumatic having a valve operatively connected therewith adapted to control the port area through which exhaust is transmitted it'rom one ont said chambers to the other, a supplemental pneumatic and connections whereby a collapsing movement of the supplemental'pneumatic influences the opening movement of said valve and a normally closed valve on the action side of the first named valve and means responsive to perforations in the music sheet for simultaneously opening said second named valve and actuating said supplemental pneumatic.

7. In combination with the striker pneumatics and exhausting means of a pneumatic musical instrument, an expression control mechanism comprising a chambered wind chest between the exhausting means andthe striker pneumatics, a pneumatic having ports communicating with different chambers in said wind chest, a valve actuable by said pneumatic for controlling the effective area of one of said ports, a plurality of supplemental pneumatics each adapted to transmit a diferent torce, and means for transmitting the movement of anyl of said supplemental pneumatics to said irst named pneumatic.

8. In combination with the striker pneumatics and exhausting means of a pneumatic musical instrument, an expression control mechanism comprising a chambered wind chest between the exhausting means and the striker pneumatics, a pneumatic having ports communicating with diferent chambers in said wind chest, a valve actuable by said pneumatic for controlling the effective area of one of said ports, a plurality of supplemental pneumatics each adapted to transmit a different force, means for transmitting the movement of any of said supplemental pneumatics to said first named pneumatic and means controlled by the music sheet for selectively actuating any one of said supplemental pneumatics.

'9. The apparatus of claim 7 in combination with tracker controlled means arranged to render one of said supplemental pneumatics non-operative in the event that tWo eXpression control ports of the tracker are simultaneously uncovered.

In Witness whereof, I have hereunto signed my name.

REINHOLD BUKOW. 

